Chaos Rising/Tarkus
Tarkus
Tarkus is a Tactical Marine Squad Sergeant of the Blood Ravens' Fourth Company.
Background
He is a strategically minded veteran of countless campaigns. Tarkus is a rock-solid second-in-command and expert tactician.
Tarkus served with Davian Thule in the Kronus campaign, and quickly established himself as one of Thule's most trusted advisors.
Missions
House Vandis Guard: "Here they come get ready to fire"
Tarkus: "Traitors!"
-Tarkus Intercepting the Traitors' Ambush
On Cold Welcome His drop-pod was hit by Surface Defenses. He barely survived the landing on Aurelia. He sacrificed himself to distract the entrenched Guardsmen of the House Vandis from the Force Commander and the other squads.
On Bloody Hand He advised the Force Commander not to ignore the Eldars. He must be deployed or he suffers from Corruption. They must fight the Avatar of Khaine.(again)
On Capital Defense If he is not deployed he will be chosen to guard the Array or Shrine.
On The Wages of Sin If he has the highest corruption. He will be the Traitor.
Tactics
He can destroy garrisoned units with his Tactical Advance (optional) and Grenade.
In the Core Campaign, Tarkus is clearly best used as a ranged defender. From cover he can Taunt enemies to attack him, drawing fire away from your advancing melee units. Armed with a Flamer and Frag grenades, he is behind only Cyrus as an anti-building/garrison unit. It is best to emphasize Stamina and Will over Ranged discipline, bringing Ranged up only to Ranged Specialist for this build- compared to your end-game damage from Avitus or Thule, his DPS is relatively low. However, most players find that his Tactical Advance skill combined with I Shall Not Fall makes him an indispensable member of your team. Armed with a flamer he can do terrific damage to swarms of light infantry, and with a Plasma Rifle he becomes a solid mass infantry/anti-tank unit. Due to the large number of supply drops found, it is rarely considered useful to take Energy skills beyond Load Out. Tactical Advance combined with Taunt means that it is a rare situation that will require him to provide cover for your entire team, and Energy-based Frag Grenades waste power best reserved for Taunt.
In Chaos Rising, Tarkus suddenly becomes very viable as a melee unit, especially once he unlocks Challenge. Challenge does more than just Taunt, it actively forces attacking units to engage Tarkus in melee combat. This includes heavy gunners and light ranged infantry and even bosses up to and including the final boss. This ability is particularly potent if combined with Cyrus' explosives or a powerful ranged support team (i.e., Commander, Dreadnought, Avitus), as it pulls enemy units out of cover and forces them into a crossfire. Because he is up in the thick of fighting, it's a good idea to keep him equipped with Frag Grenades to deal with massed enemies and Melta Bombs in case he is rushed by a Dreadnought or a tank appears. While the Energy tree had been lackluster in the core game, in Chaos Rising he gains a number of skills (such as Volley and Tactical Supremacy) that make maximizing Energy a good idea. With Energy at maximum and Melee loaded to at least Challenge, the remaining points should be allocated to Stamina to help keep him upright and moving longer before needing to use a MedKit or activate Tactical Advance. Energy management is an important part of maximizing his utility.